SOW.pdf

WD Mayo: Rev (1-27) 1 January 2020

PERFORMANCE WORK STATEMENT

W.D. MAYO L&D No. 14

CONCRETE PAVING

PART 1 – GENERAL

1.1 SCOPE OF WORK

The contractor shall furnish all labor, materials, form-work, equipment, demolition of the storage locker and remaining paving, debris removal and services required to complete all the concrete paving area work shown on the drawings and specified herein.

Option 1. Salvage and stockpile the SB1 material currently in the area to be paved.

Option 2. Flower Beds (2): The Contractor shall demolish and remove the existing bricks and concrete excluding the Curbs, Light Poles and Standards. The Contractor shall backfill and cap the flower beds with 4” of Concrete even with the top of the curb.

A site visit by prospective bidders is encouraged to determine exact site conditions and work requirements.

1.2 REFERENCES

N/A

1.3 BASIS FOR PAYMENT

Payment will be made upon completion and acceptance by the government. Payment shall be lump sum to include all costs of this contract.

1.4 WORK HOURS

Regular work hours will be from 8:00 am – 4:30 pm Monday through Friday, excluding federal holidays. Any proposed changes to the work hours must be approved by the Contracting Officer Representative (COR).

1.5 COMPLETION TIME

Work shall start NLT10 days from Notice to Proceed (NTP) and be completed in 30 calendar days after work starts.

1.6 SAFETY REQUIREMENTS

The contractor shall comply with the Corps of Engineers Safety and Health Requirements Manual, EM 385-1-1 latest edition, and all applicable Federal, State, and local safety codes and practices. It is the contractor’s responsibility to insure public safety during the entire duration of the contract. Necessary signs, barriers, warning devices, etc. shall be operated and maintained by the contractor at contractor expense. Contractor employees shall comply with the minimum dress requirements as stated in EM 385-1-1.

WD Mayo: Rev (1-27) 2 January 2020

1.7 EQUIPMENT

All equipment used to perform work under this contract shall be in good operating and mechanical condition and shall comply with Section 18 of EM 385-1-1. Equipment shall be inspected by the contractor and the inspection reports shall be submitted to the COR prior to utilization of such equipment to accomplish work on this contract.

1.8 WEATHER LIMITATIONS

Normal limitations are to be expected.

1.9 SUBMITTALS

The contractor furnish the mix specifications prior to placing concrete.

1.10 PREWORK CONFERENCE

A prework conference will be held with the COR and contractor prior to the commencement of any work. The contractor’s responsible person and necessary administrative staff (ex. QC, Safety Officer, and PM) will be required to attend this meeting. Procedures for proper invoicing and payment, schedule, etc., will be covered at this time.

1.11 ENVIRONMENTAL CLEANUP

The contractor shall maintain a clean work area at all times. The contractor shall be responsible for the protection of the environment and will be required to restore all damages subject to the approval of the contracting officer. The contractor shall remove and dispose of all debris off Government property in a state approved disposal site unless specified otherwise. The contractor will be required to comply with Federal and State environmental requirements.

1.12 COORDINATION OF WORK

All work and deliveries shall be coordinated with Paul Parris (COR) 918-775-4475 ext. 5816, Chad Kepke, Navigation Project Office, 918-775-4475, ext. 5828, or Victor Heister, Navigation Maintenance Engineer, 918-669-7244.

PART 2 – PRODUCTS

2.1 MATERIALS

Aggregate:

A 10” stabilized aggregate base shall be placed under all pavement.

Concrete Requirements:

Concrete shall be manufactured and delivered in accordance with the latest revised Standard Specification for Ready Mixed Concrete, ASTM C94. All concrete shall have a minimum 28-day compressive strength of 4,000 psi.

Concrete slump shall be:

a) 1 - 4 inches if placement and consolidation is by mechanical method such as vibratory screed;

or

WD Mayo: Rev (1-27) 3 January 2020

b) 1 - 5 inches if placement and consolidation is by other means, unless a super plasticizer is used in accordance with the manufacturer’s recommendations.

Concrete Thickness:

Parking areas and driveways, a 10″ minimum pavement thickness is required.

2.2 DELIVERY AND STORAGE

Materials shall be delivered to the site undamaged and stored out of contact with the ground.

Materials that are damaged during the delivery or improper storage shall be replaced at no cost to the government.

2.3 GOVERNMENT FURNISHED PROPERTY

N/A

PART 3 – EXECUTION

3.1 ACCOMPLISHMENT OF WORK

Demolition: The Contractor shall demolish any remaining asphalt or concrete paving to a depth sufficient to prepare the subgrade as defined below.

Subgrade Preparation:

The bottom of the excavation or the top of the fill shall be known as the pavement subgrade and shall conform to the lines, grade, and cross sections shown in the plans.

In most situations with most soils, simple removal of topsoil and excavation down to the desired pavement subgrade is sufficient preparation for the direct application of concrete pavement.

In situations where the subgrade contains sections of soft and yielding soil, such soil must be removed. It must be replaced with a material (or soil) that will, after compaction, bring the subgrade to a firm, unyielding; and uniformly dense condition. (If soil is used as a replacement material, it should be compacted at or slightly above optimum moisture.)

All trenches and structure excavations shall be backfilled to natural or finished grade with granular material or controlled density fill as soon as conditions permit. All backfill shall be compacted with mechanical tampers in layers not over 6 inches in compacted thickness to densities similar to that of surrounding soils. Under these conditions, no other base or subgrade material is required.

Following demolition and before paving the Contractor shall install a buried 2” conduit from the Control House to the southern edge of the paving to a location determined by the Government.

Concrete Placement:

Ready mixed concrete hauled in truck mixers or truck agitators shall be mixed and delivered in accordance with ASTM C-94. Before placing concrete, freestanding water, snow, ice, or other foreign materials shall be removed from subgrade. All forms shall be thoroughly cleaned, WD Mayo: Rev (1-27) 4 January 2020 secured in position, and coated with a form release agent. Concrete shall not be placed on a soft, spongy, frozen, or otherwise unsuitable subgrade. The subgrade shall be damp when concrete is placed.

Concrete shall be placed, struck off, and consolidated to plan grade with a mechanical placement machine, vibrating screed, or by hand finishing methods when approved. In lieu of fixed forms, the contractor may place concrete with a slip form paver designed to spread, consolidate, screed, and float finish the freshly placed concrete in one complete pass of the machine. Pavement shall be pitched to area drains or perimeter areas to remove water.

6”x6”-W2.9xW2.9 (6”x6”-6x6) reinforcement is required.

Finishing:

After concrete has been struck off and consolidated, a bull float may be used to remove any high or low spots. Bull float use shall be confined to a minimum. Mechanical finishing machine floating is acceptable; however, under no circumstances shall the concrete surface be steel troweled.

A final skid resistant finish shall be made with a burlap drag or broom.

Curing and Protection:

Concrete must be cured by protecting it from loss of moisture, rapid temperature change and mechanical injury according to the latest edition of ACI 301. When concrete is being placed in cold weather and the temperature may drop below 35·F., straw, hay, insulated curing blankets, or other suitable material shall be provided along the line of work to prevent freezing of concrete.

Concrete injured by frost action shall be removed and replaced at the contractor’s expense.

Joints:

Unless shown on the project drawings, a joining plan shall be prepared by the contractor and approved before paving begins. Typical drying shrinkage cracking must be minimized and controlled by proper jointing. To minimize and control cracking, joints shall be:

a) Continuous across the slab;

b) Symmetrical (in squares or rectangles where possible);

c) Spaced at no more than 2 1/2 times in feet the slab thickness in inches. (For example, the maximum joint spacing of a 4 inch thick slab would be 10 feet.)

Isolation joints (expansion joints) shall be used to isolate fixed objects abutting or within the paved area. They shall contain premolded joint filler for the full depth of the slab.

Control joints (contraction joints) should be produced by sawing (preferred), hand-tooling, or forming by use of premolded filler. Joint depth shall be a minimum of one-fourth the slab thickness. Hand-tooled joints shall have a maximum edge radius of 1/4 inch. Sawing of joints shall begin as soon as the concrete has hardened sufficiently to permit sawing without excessive raveling. All joints shall be completed before uncontrolled shrinkage cracking occurs.

WD Mayo: Rev (1-27) 5 January 2020

Construction joints (joints ending a day’s pour) must allow wheel load transfer across the joints where necessary. In such cases, these joints shall be keyed or dowelled.

Joints shall extend completely through the curb when the curb is integrally formed with the slab.

Construction and control joint openings wider than 1/4 inch shall be cleaned and sealed before opening parking area to traffic. (Isolation joints will not require sealing.)

When approved, the contractor shall be permitted to make minor adjustments in joint location to make them coincide with drainage or other structures.

Option 1. Salvage and stockpile the SB1 material currently in the area to be paved.

Option 2. Flower Beds (2): The Contractor shall demolish and remove the existing bricks and concrete excluding the Curbs, Light Poles and Standards. The Contractor shall backfill and cap with 4” of Concrete even with the top of the curb.

3.2 TESTING

N/A

3.3 WARRANTY

Warranty shall cover manufactures recommended product installation and specifications for a period of one year.